Study on the effect of counter ball materials on fretting wear behavior of solid lubricating films

Solid self-lubricating film can undoubtedly play a superior role in improving the micromotion behavior. The friction pairs of different materials have different fretting behavior and wear mechanism due to their different mechanical properties and surface adhesion properties. Investigating the influence of mechanical properties and surface adhesion on the fretting behavior can make the self-lubricating solid film play a better effect in the practical fretting working conditions. Here, DLC film and MoS2 film are deposited on AISI 304 stainless steel using a TeerUDP-650 unbalanced magnetron sputtering system. The fretting performance of DLC and MoS2 films resistance to GCr15, Al2O3, SiC and Si3N4 balls are studied. The results demonstrate that the fretting characteristics of DLC film are highly dependent on the mechanical properties and adhesion behavior of counter balls. Thereinto, Al2O3 balls show excellent fretting behavior, while SiC and Si3N4 balls make DLC film ineffective due to their high hardness and high adhesion. The MoS2 film maintains low friction and low wear state against any counter ball. DLC film achieves anti-fretting wear via graphitization, while MoS2 film primarily relies on slip and plastic flow. This work provides a theoretical reference for proper selection of solid lubricating films and counter balls under practical fretting conditions and reveals the different tribological mechanisms of friction pairs.